[Federal Register Volume 80, Number 141 (Thursday, July 23, 2015)]
[Notices]
[Pages 43710-43719]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-18021]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XD829
Taking of Marine Mammals Incidental to Specified Activities;
Construction of the East Span of the San Francisco-Oakland Bay Bridge
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that we have issued an incidental harassment authorization (IHA) to
California Department of Transportation (CALTRANS) to incidentally
harass, by Level B harassment only, four species of marine mammals
during activities related to the construction of Pier 3 of the East
Span of the San Francisco-Oakland Bay Bridge (SF-OBB) in California
DATES: This authorization is effective from July 15, 2015 through July
14, 2016.
FOR FURTHER INFORMATION CONTACT: Robert Pauline, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
An electronic copy of CALTRANS' application and supporting
documents, as well as a list of the references cited in this document,
may be obtained by visiting the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing
these documents, please call the contact listed above (see FOR FURTHER
INFORMATION CONTACT).
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a notice of a proposed authorization is
provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103
as ``. . . an impact resulting from the specified activity that cannot
be reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.''
Section 101(a)(5)(D) of the MMPA established an expedited process
by which citizens of the U.S. can apply for an authorization to
incidentally take small numbers of marine mammals by harassment.
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS' review
of an application followed by a 30-day public notice and comment period
on any proposed authorizations for the incidental harassment of marine
mammals. Within 45 days of the close of the comment period, NMFS must
either issue or deny the authorization. Except with respect to certain
activities not pertinent here, the MMPA defines ``harassment'' as ``any
act of pursuit, torment, or annoyance which (i) has the potential to
injure a
[[Page 43711]]
marine mammal or marine mammal stock in the wild [Level A harassment];
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering [Level B harassment].''
Summary of Request
On December 15, 2014, CALTRANS submitted its most recent request to
NOAA requesting an IHA for the possible harassment of small numbers of
California sea lions (Zalophus californianus), Pacific harbor seals
(Phoca vitulina richardsii), harbor porpoises (Phocoena phocoena), and
gray whales (Eschrichtius robustus) incidental to construction
associated with a replacement bridge for the East Span of the SF-OBB,
in San Francisco Bay (SFB, or Bay), California.
An IHA was previously issued to CALTRANS for this activity on
January 8, 2014 (79 FR 2421; January 14, 2014), based on activities
described on CALTRANS' IHA application dated April 13, 2013. That IHA
expired on January 7, 2015. Since the construction activity would
continue for another two years, CALTRANS requests to renew its IHA. In
its IHA renewal request, CALTRANS also states that there has been no
change in the scope of work for the SF-OBB Project from what was
outlined in its April 13, 2013, IHA application project description,
the Federal Register notice for the proposed IHA (78 FR 60852; October
2, 2013), and the Federal Register notice for the issuance of that IHA
(79 FR 2421; January 14, 2014). On November 10, 2003, NMFS issued the
first project-related IHA authorizing the take of small numbers of
marine mammals incidental to the construction of the SFOBB Project.
CALTRANS has been issued a total of seven subsequent IHAs for the SF-
OBB Project to date, excluding the application currently under review.
Description of the Specified Activity
Overview
Construction activities for the replacement of the SF-OBB East Span
commenced in 2002 and are expected to be completed in 2016 with the
completion of the bike/pedestrian path and eastbound on ramp from Yerba
Buena Island. The new east span is now open to traffic.
This stage of the project covered under the IHA will include the
mechanical dismantling of marine foundations of the East Span of the
bridge as well as the installation of approximately 200 steel piles.
Dates and Duration
In-water activities are expected to begin in July 2015. Up to 128
days of pile driving may occur under the IHA. However, the schedule for
this project is highly variable. As such, activities covered under this
IHA may occur anytime between July 15, 2015 and July 14, 2016 which are
the effective dates of the IHA.
Specific Geographic Region
The project site is located in San Francisco Bay around the east
span of the SFOBB.
Detailed Description of Activities
We provided a description of the proposed action in our Federal
Register notice announcing the proposed authorization (80 FR 23774;
April 29, 2015). Please refer to that document; we provide only summary
information here.
The proposed action would involve the mechanical dismantling of
marine foundations and superstructure components of the East Span of
the bridge as well as the installation of approximately 200 steel
piles. These piles include 0.45-meter, 0.61-meter, 0.91-meter (18-inch,
24-inch, and 36-inch) diameter pipe piles, and 0.34 meter (14-inch) H-
piles on up to 128 days. These piles will be installed in the water to
construct temporary supports between Piers E4-E8, which will help with
the dismantling process by providing support to the original bridge
superstructure as it is taken down. Both vibratory and impact hammers
could be used to install pipe piles depending on the substrate. In
addition, CALTRANS would remove various bridge superstructures
including trusses, road decks, and steel and concrete support towers.
The concrete foundation of the bridge would be removed using various
mechanical means including saw cutting, flame cutting, mechanical
splitting, drilling, pulverizing, and/or hydrocutting. Some of the
installed piles may be removed under this IHA, but the contractor has
until 2018 to remove all 200 piles.
Comments and Responses
A notice of NMFS' proposal to issue an IHA was published in the
Federal Register on April 29, 2015 (80 FR 23774). During the 30-day
public comment period, the Marine Mammal Commission submitted a letter.
The letter is available on the Internet www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. All comments specific to CALTRANS'
application that address the statutory and regulatory requirements or
findings NMFS must make to issue an IHA are addressed in this section
of the Federal Register notice.
Comment 1: The Commission noted that during the last authorization
marine mammal monitoring did not occur 100 percent of time spent on
activities authorized under the IHA. The Commission believes that this
results in underestimates the number of takes of marine mammals known
to occur in the project area. Monitoring during all in-water sound-
producing activities is the only way for CALTRANS and NMFS to be
confident that the numbers of marine mammals taken are within the
limits authorized and the least practicable impact occurs. For these
reasons, the Commission recommended that NMFS require CALTRANS to
implement full-time monitoring of Level A and B harassment zones during
all in- water sound-producing activities (i.e., pile driving and
dismantling activities).
Response 1: NMFS does not agree with the Commission's
recommendation. NMFS had discussed with CALTRANS specific protocols
concerning marine mammal monitoring during its proposed in-water
construction activities. As described in detail in the Federal Register
notice for the previous proposed IHA (79 FR 2421; January 14, 2014) and
in CALTRANS' IHA application, CALTRANS' planned construction includes
installation of up to 635 temporary falsework piles, 1,925 steel sheet
piles, and various mechanical dismantling activities over several
years. The extent of the work made it infeasible and costly to
implement marine mammal monitoring for Level A and B harassment zones
at all times, particularly since some of the Level B harassment zones
for vibratory pile driving extend to a radius of 2 km. CALTRANS will
monitor the 180 and 190 dB exclusion zones and 160 dB behavioral
harassment zone for all unattenuated impact pile driving of H-piles,
and the 180 and 190 dB exclusion zones for attenuated impact pile
driving and mechanical dismantling, thereby minimizing the possibility
of injury. Further, for the purposes of better understand behavioral
efforts, CALTRANS will also monitor the 160 dB behavioral harassment
zone for 20% of the attenuated impact pile driving, and 120 dB
behavioral harassment zone for 20% of vibratory pile driving and
mechanic dismantling. Results have been extrapolated in past monitoring
reports and will continue to be extrapolated in the future reports.
Results of past monitoring reports are
[[Page 43712]]
discussed later in this notice in the section in Monitoring and
reporting. CALTRANS, however, will not monitor the unattenuated impact
pile proofing, which only lasts for less than one minute. Proposed
proofing of piles will be limited to a maximum of two piles per day,
and for less than 1 minute per pile, administering a maximum of twenty
blows per pile. CALTRANS states, and NMFS agrees, that the logistics of
scheduling and mobilizing a monitoring team for activities that will
last less than one minute is not practical.
Comment 2: The Commission noted that each authorization under
section 101(a)(5)(D) is a separate undertaking and should contain
sufficient information to allow for meaningful public review and
comment. The Commission recommended in 2013 that NMFS include in each
proposed incidental harassment authorization it publishes in the
Federal Register a detailed description of the proposed activities
rather than referring to previous documents. NMFS agreed and stated
that it would provide such detailed descriptions in the Federal
Register notices moving forward (see 79 FR 2422). However, NMFS'
current notice did not include such a description. The Commission again
recommends that NMFS include in each proposed incidental harassment
authorization published in the Federal Register a detailed description
of the proposed activities rather than referring to previous documents.
Response 2: The CALTRANS bridge project is a multi-year, multi-
stage construction initiative. The schedule and scope of this project
have undergone multiple revisions. NMFS felt that it captured the
essential elements of what is proposed to occur under the proposed
authorization under review. NMFS has added additional information to
the Detailed Description of Activity section of this Federal Register
Notice. NMFS will include a comprehensive description of proposed
activities in future proposed notices.
Description of Marine Mammals in the Area of the Specified Activity
There are four marine mammal species known to occur in the vicinity
of the SF-OBB in California which may be subjected to Level B
harassment. These are the Pacific harbor seal, California sea lion,
gray whale, and harbor porpoise.
We have reviewed CALTRANS' detailed species descriptions, including
life history information, for accuracy and completeness and refer the
reader to Section 3 of CALTRANS' application as well as the proposed
incidental harassment authorization published in the Federal Register
(80 FR 23774) instead of reprinting the information here. Please also
refer to NMFS' Web site (www.nmfs.noaa.gov/pr/species/mammals) for
generalized species accounts which provide information regarding the
biology and behavior of the marine resources that occur in SE Alaska.
We provided additional information for the potentially affected stocks,
including details of stock-wide status, trends, and threats, in our
Federal Register notice of proposed authorization (80 FR 23774).
Table 1 lists marine mammal stocks that could occur in the vicinity
of the SFOBB project that may be subject to Level B harassment and
summarizes key information regarding stock status and abundance.
Taxonomically, we follow Committee on Taxonomy (2014). Please see NMFS'
Stock Assessment Reports (SAR), available at www.nmfs.noaa.gov/pr/sars,
for more detailed accounts of these stocks' status and abundance.
Table 1--List of Marine Mammal Species Under NMFS Jurisdiction That Occur in the Vicinity of SF-OBB Project Area
*
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Stock Population
Common name Stock Scientific name ESA Status abundance trend
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Harbor Seal................. California..... Phoca vitulina. Not listed..... 30,196 Decreasing.
California sea lion......... United States.. Zalophus Not listed..... 296,750 Increasing.
californianus.
Gray whale.................. Eastern North Eschrichtius Not listed..... 19,126 Increasing.
Pacific Stock. robustus.
Harbor porpoise............. San Francisco- Phocoena Not listed..... 9,886 Stable.
Russian River. phocoena.
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* Estimated abundance numbers come primarily from NMFS 2014 Pacific Marine Mammal Stock Assessment Report
(Carretta et al. 2014).
Potential Effects of the Specified Activity on Marine Mammals
The Federal Register notice of proposed authorization (80 FR
23744), incorporated here by reference, provides a general background
on sound relevant to the specified activity as well as a detailed
description of marine mammal hearing and of the potential effects of
these construction activities on marine mammals.
Anticipated Effects on Habitat
We described potential impacts to marine mammal habitat in detail
in our Federal Register notice of proposed authorization. In summary,
the project activities would not modify existing marine mammal habitat.
The activities may cause some fish to leave the area of disturbance,
thus temporarily impacting marine mammals' foraging opportunities in a
limited portion of the foraging range; but, because of the short
duration of the activities and the relatively small area of the habitat
that may be affected, the impacts to marine mammal habitat are not
expected to cause significant or long-term negative consequences for
individual marine mammals or their populations
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, ``and other means of effecting the least practicable impact
on such species or stock and its habitat, paying particular attention
to rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking'' for certain
subsistence uses.
Measurements from similar pile driving events were coupled with
practical spreading loss to estimate zones of influence (ZOI; see
``Estimated Take by Incidental Harassment''). ZOIs are often used to
establish a mitigation zone around each pile (when deemed practicable)
to prevent Level A harassment to marine mammals, and also provide
estimates of the areas within which Level B harassment might occur.
ZOIs may vary between different diameter piles and types of
installation methods. CALTRANS will employ the following mitigation
measures:
(a) Conduct briefings between construction supervisors and crews,
marine mammal monitoring team, and CALTRANS staff prior to the start of
all
[[Page 43713]]
pile driving activity, and when new personnel join the work, in order
to explain responsibilities, communication procedures, marine mammal
monitoring protocol, and operational procedures.
(b) For in-water heavy machinery work other than pile driving
(using, e.g., standard barges, tug boats, barge-mounted excavators, or
clamshell equipment used to place or remove material), if a marine
mammal comes within 10 m, operations shall cease and vessels shall
reduce speed to the minimum level required to maintain steerage and
safe working conditions. This type of work could include the following
activities: (1) Movement of the barge to the pile location or (2)
positioning of the pile on the substrate via a crane (i.e., stabbing
the pile).
Monitoring and Shutdown for Pile Driving
The following measures apply to CALTRANS' mitigation through
shutdown and disturbance zones:
Shutdown Zone--For all pile driving activities, CALTRANS will
establish shutdown zones in which SPLs equal or exceed the 180/190 dB
rms acoustic injury criteria to define the areas where shutdown of
activity will occur upon sighting of a marine mammal (or in
anticipation of an animal entering the defined area), thus preventing
injury of marine mammals. For impact driving this is 235 meters. For
vibratory driving, CALTRANS's activities are not expected to produce
sound at or above the 180 dB rms injury criterion. Before the sizes of
actual zones are determined based on hydroacoustic measurements,
CALTRANS shall establish this zone based on prior measurements
conducted during SF-OBB constructions, as described in Table 1 of this
document. CALTRANS will also implement a minimum shutdown zone of 10 m
radius for all marine mammals around all vibratory pile driving and
removal activity and 100 m radius around any dismantling activity.
These precautionary measures are intended to further reduce the
unlikely possibility of injury from direct physical interaction with
construction operations.
Disturbance Zone--Disturbance zones are the areas in which SPLs
equal or exceed 120 dB rms (for continuous sound) for pile driving
installation and removal. This is 2,000 meters for vibratory driving
and 1,000 meters for impact driving. Disturbance zones provide utility
for monitoring conducted for mitigation purposes (i.e., shutdown zone
monitoring) by establishing monitoring protocols for areas adjacent to
the shutdown zones. Monitoring of disturbance zones enables observers
to be aware of and communicate the presence of marine mammals in the
project area but outside the shutdown zone and thus prepare for
potential shutdowns of activity. However, the primary purpose of
disturbance zone monitoring is for documenting incidents of Level B
harassment; disturbance zone monitoring is discussed in greater detail
later (see ``Monitoring and Reporting''). Nominal radial distances for
disturbance zones are shown in Table 1.
Table 1--Temporary exclusion and Level B Harassment Zones for Various Pile Driving and Dismantling Activities
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Distance to Distance to Distance to Distance to
Pile driving/dismantling 120 dB re 1 160 dB re 1 180 dB re 1 190 dB re 1
activities Pile size (m) [micro]Pa [micro]Pa [micro]Pa [micro]Pa
(rms) (m) (rms) (m) (rms) (m) (rms) (m)
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Vibratory Driving............. 24.............. 2,000 NA NA NA
36.............. 2,000 NA NA NA
Sheet pile...... 2,000 NA NA NA
Attenuated Impact Driving..... 24.............. NA 1,000 235 95
36.............. NA 1,000 235 95
Unattenuated Proofing......... 24.............. NA 1,000 235 95
36.............. NA 1,000 235 95
Unattenuated Impact Driving... H-pile.......... NA 1,000 235 95
Dismantling................... ................ 2,000 NA 100 100
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Once hydroacoustic measurements of pile driving and mechanical
dismantling activities have been conducted, CALTRANS shall revise the
sizes of the zones based on actual measurements.
Use of Noise Attenuation Devices--To reduce impact on marine
mammals, CALTRANS shall use a marine pile driving energy attenuator
(i.e., air bubble curtain system), or other equally effective sound
attenuation method (e.g., dewatered cofferdam) for all impact pile
driving, with the exception of pile proofing or impact driving of H-
piles.
In order to document observed incidents of harassment, observers
record all marine mammal observations, regardless of location. The
observer's location, as well as the location of the pile being driven,
is known from a GPS. The location of the animal is estimated as a
distance from the observer, which is then compared to the location from
the pile and the estimated ZOIs for relevant activities (i.e., pile
installation and removal). This information may then be used to
extrapolate observed takes to reach an approximate understanding of
actual total takes.
Time Restrictions--Work will occur only during daylight hours, when
visual monitoring of marine mammals can be conducted. In addition, all
in-water construction will be limited to the period between July 15,
2015 and July 14, 2016.
Soft Start--The use of a soft start procedure is believed to
provide additional protection to marine mammals by warning or providing
a chance to leave the area prior to the hammer operating at full
capacity, and typically involves a requirement to initiate sound from
the hammer at reduced energy followed by a waiting period. This
procedure is repeated two additional times. It is difficult to specify
the reduction in energy for any given hammer because of variation
across drivers and, for impact hammers, the actual number of strikes at
reduced energy will vary because operating the hammer at less than full
power results in ``bouncing'' of the hammer as it strikes the pile,
resulting in multiple ``strikes.'' The project will utilize soft start
techniques for both impact and vibratory pile driving. We require
CALTRANS to initiate sound from vibratory hammers for fifteen seconds
at reduced energy followed by a thirty-second waiting period, with the
procedure repeated two additional times. For impact driving, we require
an
[[Page 43714]]
initial set of three strikes from the impact hammer at reduced energy,
followed by a thirty-second waiting period, then two subsequent three
strike sets. Soft start will be required at the beginning of each day's
pile driving work and at any time following a cessation of pile driving
of 20 minutes or longer (specific to either vibratory or impact
driving).
Power Down and Shut-down--Although power down and shut-down
measures will not be required for impact pile driving and removal
activities due to the nature of sediments in the Bay, these measures
will be required for mechanical dismantling activities. The contractor
performing mechanical dismantling work will stop in-water noise
generation.
Monitoring
Monitoring Protocols--Monitoring would be conducted before, during,
and after pile driving, pile and mechanical dismantling. In addition,
observers shall record all incidents of marine mammal occurrence,
regardless of distance from activity, and shall document any behavioral
reactions in concert with distance from piles being driven.
Observations made outside the shutdown zone will not result in shutdown
and that pile segment would be completed without cessation, unless the
animal approaches or enters the shutdown zone, at which point all pile
driving activities would be halted, except in the case of impact
driving when driving will be allowed to continue. Monitoring will take
place from thirty minutes prior to initiation through thirty minutes
post-completion of pile driving activities. Pile driving activities
include the time to remove a single pile or series of piles, as long as
the time elapsed between uses of the pile driving equipment is no more
than thirty minutes.
The following additional measures apply to visual monitoring:
(1) Monitoring will be conducted by qualified observers, who will
be placed at the best vantage point(s) practicable to monitor for
marine mammals and implement shutdown/delay procedures when applicable
by calling for the shutdown to the hammer operator. Qualified observers
are trained biologists, with the following minimum qualifications:
(a) Visual acuity in both eyes (correction is permissible)
sufficient for discernment of moving targets at the water's surface
with ability to estimate target size and distance; use of binoculars
may be necessary to correctly identify the target;
(b) Advanced education in biological science or related field
(undergraduate degree or higher required);
(c) Experience and ability to conduct field observations and
collect data according to assigned protocols (this may include academic
experience);
(d) Experience or training in the field identification of marine
mammals, including the identification of behaviors;
(e) Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
(f) Writing skills sufficient to prepare a report of observations
including but not limited to the number and species of marine mammals
observed; dates and times when in-water construction activities were
conducted; dates and times when in-water construction activities were
suspended to avoid potential incidental injury from construction sound
of marine mammals observed within a defined shutdown zone; and marine
mammal behavior; and
(g) Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
(2) Prior to the start of pile driving activity, the shutdown zone
will be monitored for 30 minutes to ensure that it is clear of marine
mammals. Pile driving will only commence once observers have declared
the shutdown zone clear of marine mammals; animals will be allowed to
remain in the shutdown zone (i.e., must leave of their own volition)
and their behavior will be monitored and documented. The shutdown zone
may only be declared clear, and pile driving started, when the entire
shutdown zone is visible (i.e., when not obscured by dark, rain, fog,
etc.).
If a marine mammal approaches or enters the shutdown zone during
the course of vibratory pile driving operations, activity will be
halted and delayed until he animal has voluntarily left and been
visually confirmed beyond the shutdown zone. If a marine mammal is seen
above water and then dives below, the contractor would wait 15 minutes
for pinnipeds and harbor porpoise and 30 minutes for gray whale. If no
marine mammals are seen by the observer in that time it will be assumed
that the animal has moved beyond the exclusion zone.
Monitoring will be conducted throughout the time required to drive
a pile. In impact driving situations, once the pile driving of a
segment begins it will not be stopped until that segment has reached
its predetermined depth due to the nature of the sediments underlying
the Bay. If impact pile driving were to stop and then resumes, it would
potentially have to occur for a longer time and at increased energy
levels. If marine mammals enter the safety zone after pile driving of a
segment has begun, pile driving will continue and marine mammal
observers will monitor and record marine mammal numbers and behavior.
(3) The area within the Level B harassment zone shall be conducted
by a minimum of three qualified NMFS-approved marine mammal observers
(MMOs) placed in strategic locations that will afford visual coverage
of these zones. Observers may be stationed on boats, Yerba Buena Island
and/or Treasure Island, the new bridge or construction barges. Marine
mammal presence within the Level B harassment zone will be monitored,
but vibratory and impact pile driving as well as dismantling activity
will not be stopped if marine mammals are found to be present. Any
marine mammal documented within the Level B harassment zone during
vibratory and impact driving or mechanical dismantling activities would
constitute a Level B take (harassment), and will be recorded and
reported as such.
Mitigation Conclusions
We have carefully evaluated CALTRANS' proposed mitigation measures
and considered their effectiveness in past implementation to determine
whether they are likely to effect the least practicable impact on the
affected marine mammal species and stocks and their habitat. Our
evaluation of potential measures included consideration of the
following factors in relation to one another: (1) The manner in which,
and the degree to which, the successful implementation of the measure
is expected to minimize adverse impacts to marine mammals, (2) the
proven or likely efficacy of the specific measure to minimize adverse
impacts as planned; and (3) the practicability of the measure for
applicant implementation.
Any mitigation measure(s) we prescribe should be able to
accomplish, have a reasonable likelihood of accomplishing (based on
current science), or contribute to the accomplishment of one or more of
the general goals listed below:
(1) Avoidance or minimization of injury or death of marine mammals
wherever possible (goals 2, 3, and 4 may contribute to this goal).
(2) A reduction in the number (total number or number at
biologically
[[Page 43715]]
important time or location) of individual marine mammals exposed to
stimuli expected to result in incidental take (this goal may contribute
to 1, above, or to reducing takes by behavioral harassment only).
(3) A reduction in the number (total number or number at
biologically important time or location) of times any individual marine
mammal would be exposed to stimuli expected to result in incidental
take (this goal may contribute to 1, above, or to reducing takes by
behavioral harassment only).
(4) A reduction in the intensity of exposure to stimuli expected to
result in incidental take (this goal may contribute to 1, above, or to
reducing the severity of behavioral harassment only).
(5) Avoidance or minimization of adverse effects to marine mammal
habitat, paying particular attention to the prey base, blockage or
limitation of passage to or from biologically important areas,
permanent destruction of habitat, or temporary disturbance of habitat
during a biologically important time.
(6) For monitoring directly related to mitigation, an increase in
the probability of detecting marine mammals, thus allowing for more
effective implementation of the mitigation.
Based on our evaluation of CALTRANS' proposed measures, including
information from monitoring of implementation of mitigation measures
very similar to those described here under previous IHAs from other
marine construction projects, we have determined that the proposed
mitigation measures provide the means of effecting the least
practicable impact on marine mammal species or stocks and their
habitat, paying particular attention to rookeries, mating grounds, and
areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth ``requirements pertaining to
the monitoring and reporting of such taking''. The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate that requests for
incidental take authorizations must include the suggested means of
accomplishing the necessary monitoring and reporting that will result
in increased knowledge of the species and of the level of taking or
impacts on populations of marine mammals that are expected to be
present in the proposed action area.
Any monitoring requirement we prescribe should improve our
understanding of one or more of the following:
(1) An increase in the probability of detecting marine mammals,
both within the mitigation zone (thus allowing for more effective
implementation of the mitigation) and in general to generate more data
to contribute to the analyses mentioned below;
(2) An increase in our understanding of how many marine mammals are
likely to be exposed to levels of pile driving that we associate with
specific adverse effects, such as behavioral harassment, TTS, or PTS;
(3) An increase in our understanding of how marine mammals respond
to stimuli expected to result in take and how anticipated adverse
effects on individuals (in different ways and to varying degrees) may
impact the population, species, or stock (specifically through effects
on annual rates of recruitment or survival) through any of the
following methods:
[ssquf] Behavioral observations in the presence of stimuli compared
to observations in the absence of stimuli (need to be able to
accurately predict received level, distance from source, and other
pertinent information);
[ssquf] Physiological measurements in the presence of stimuli
compared to observations in the absence of stimuli (need to be able to
accurately predict received level, distance from source, and other
pertinent information);
[ssquf] Distribution and/or abundance comparisons in times or areas
with concentrated stimuli versus times or areas without stimuli;
(4) An increased knowledge of the affected species; and
(5) An increase in our understanding of the effectiveness of
certain mitigation and monitoring measures.
CALTRANS has submitted monitoring reports for each of the IHAs that
have been issued to them for this project. NMFS received the most
recent report on April 28, 2015 covering the IHA issued for the period
between January 8, 2014 and January 7, 2015. CALTRANS observed all
required monitoring and mitigation protocols during this period.
Recorded takes were below permitted levels for all species except for
harbor seals. After extrapolating observed numbers during 30 percent of
driving activities, CALTRANS determined that 130 harbor seals were
taken. This exceeded the allowable take limit of 50 stated in the IHA.
CALTRANS reported that most of these seals were within the ZOI in Coast
Guard Cove and Clipper Cove north of Yurba Buena Island (YBI) as well
as an area 200-400 m off the southeast shore of YBI. Most seals
appeared to be foraging and none showed any response to pile driving
noise and continued to forage in those areas for up to several hours
during pile driving. Based on the high number of harbor seal takes
recorded, CALTRANS has requested an increase in takes under the IHA
discussed in this Federal Register Notice. NMFS has approved an
increase in harbor seal takes, which is discussed in a following
section.
CALTRANS consulted with NMFS to create a marine mammal monitoring
plan as part of the IHA application for this project.
Visual Marine Mammal Observations
CALTRANS will implement onsite marine mammal monitoring
for 100% of all unattenuated impact pile driving of H-piles for 180-
and 190-dB re 1 [mu]Pa exclusion zones (235 meter radius) and 160-dB re
1 [mu]Pa Level B harassment zone, attenuated impact pile driving
(except pile proofing) and mechanical dismantling for 180- and 190-dB
re 1 [mu]Pa exclusion zones. CALTRANS will also monitor 20% of the
attenuated impact pile driving for the 160-dB re 1 [mu]Pa Level B
harassment zone (1,000 meter radius), and 20% of vibratory pile driving
and mechanic dismantling for the 120-dB re 1 [mu]Pa Level B harassment
zone (2,000 meter radius).
Three individuals meeting the minimum qualification
previously identified will monitor the Level A and B harassment zones
during impact pile driving and the Level B harassment zone during
vibratory pile driving and dismantling. Monitors may be stationed on
boats, Yerba Buena Island and/or Treasure Island, the new bridge or
construction barges.
During impact pile driving, the area within 235 meters of
pile driving activity will be monitored and maintained as marine mammal
buffer area in which pile installation will not commence if any marine
mammals are observed within or approaching the area of potential
disturbance. If a marine mammal approaches or appears within the zone,
pile driving of a segment will continue until that segment has reached
its predetermined depth due to the nature of the sediments underlying
the Bay.
The area within the Level B harassment threshold for
impact driving will be monitored by three field monitors stationed in a
positon permitting visual access to the 1,000 meter limit of the Level
B harassment zone. Marine mammal presence within this Level B
harassment zone, if any, will be monitored, but impact pile driving
activity will not be stopped if marine mammals are found to be present.
Any marine mammal
[[Page 43716]]
documented within the Level B harassment zone during impact driving
would constitute a Level B take (harassment), and will be recorded and
reported as such.
During vibratory pile driving, the area within 10 meters
of pile driving activity will be monitored and maintained as a marine
mammal buffer area in which pile installation will not commence or will
be suspended temporarily if any marine mammals are observed within or
approaching the area of potential disturbance. The Level B harassment
area with a 2,000 meter radius will be monitored by three qualified
observers stationed at strategic locations that provide adequate visual
coverage of the disturbance zone. The monitoring staff will record any
presence of marine mammals by species, will document any behavioral
responses noted, and record Level B takes when sightings overlap with
pile installation activities.
During mechanical dismantling activities a 100 meters
radius will be monitored and maintained as a marine mammal buffer area
in which pile installation will not commence or will be suspended
temporarily if any marine mammals are observed within or approaching
the area.
The individuals will scan the waters within each
monitoring zone activity using binoculars (Vector 10X42 or equivalent),
spotting scopes (Swarovski 20-60 zoom or equivalent), and visual
observation.
The area within which the Level B harassment thresholds
could be exceeded during impact pile driving and vibratory pile driving
will be monitored for the presence of marine mammals during all impact
and vibratory pile driving. Marine mammal presence within these zones,
if any, will be monitored but pile driving activity will not be stopped
if marine mammals were found to be present. Any marine mammal
documented within the Level B harassment zone will constitute a Level B
take, and will be recorded and used to document the number of take
incidents.
If waters exceed a sea-state which restricts the
observers' ability to make observations within the marine mammal buffer
zone (the 235 meter radius) (e.g., excessive wind or fog), impact pile
installation will cease until conditions allow the resumption of
monitoring.
The waters will be scanned for 30 minutes before, during,
and 30 minutes after any and all pile driving and removal activities.
If marine mammals enter or are observed within the
designated marine mammal buffer zone (the 235m radius) during or 30
minutes prior to pile driving, the monitors will notify the on-site
construction manager to not begin until the animal has moved outside
the designated radius.
If a marine mammal approaches the Level A harassment zone
prior to initiation of pile driving, CALTRANS cannot commence
activities until the marine mammal (a) is observed to have left the
Level A harassment zone or (b) has not been seen or otherwise detected
within the Level A harassment zone for 30 minutes.
The waters will continue to be scanned for at least 30
minutes after pile driving has completed each day, and after each
stoppage of 30 minutes or greater.
Data Collection
We require that observers use approved data forms. Among other
pieces of information, CALTRANS will record detailed information about
any implementation of shutdowns, including the distance of animals to
the pile and description of specific actions that ensued and resulting
behavior of the animal, if any. In addition, CALTRANS will attempt to
distinguish between the number of individual animals taken and the
number of incidents of take. We require that, at a minimum, the
following information be collected on the sighting forms:
Date and time that monitored activity begins or ends;
Construction activities occurring during each observation
period;
Weather parameters (e.g., percent cover, visibility);
Water conditions (e.g., sea state, tide state);
Species, numbers, and, if possible, sex and age class of
marine mammals;
Description of any observable marine mammal behavior
patterns, including bearing and direction of travel and distance from
pile driving activity;
Distance from pile driving activities to marine mammals
and distance from the marine mammals to the observation point;
Locations of all marine mammal observations; and
Other human activity in the area.
Reporting
CALTRANS will notify NMFS prior to the initiation of the pile
driving and dismantling activities for the removal of the existing east
span. NMFS will be informed of the initial sound pressure level
measurements for both pile driving and foundation dismantling
activities, including the final exclusion zone and Level B harassment
zone radii established for impact and vibratory pile driving and marine
foundation dismantling activities.
Monitoring reports will be posted on the SF-OBB Project's
biological mitigation Web site (www.biomitigation.org) on a weekly
basis if in-water construction activities are conducted. Marine mammal
monitoring reports will include species and numbers of marine mammals
observed, time and location of observation and behavior of the animal.
In addition, the reports will include an estimate of the number and
species of marine mammals that may have been harassed as a result of
activities.
CALTRANS will provide NMFS with a draft monitoring report within 90
days of the conclusion of the proposed construction work. This report
will detail the monitoring protocol, summarize the data recorded during
monitoring, and estimate the number of marine mammals that may have
been harassed. If no comments are received from NMFS within 30 days,
the draft final report will constitute the final report. If comments
are received, a final report must be submitted within 30 days after
receipt of comments.
Estimated Take by Incidental Harassment
Except with respect to certain activities not pertinent here,
section 3(18) of the MMPA defines ``harassment'' as: ``. . . any act of
pursuit, torment, or annoyance which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild [Level A harassment];
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering [Level B harassment].''
All anticipated takes would be by Level B harassment resulting from
impact and vibratory pile driving/removal and involving temporary
changes in behavior. Injurious or lethal takes are not expected due to
the expected source levels and sound source characteristics associated
with the activity, and the planned mitigation and monitoring measures
are expected to further minimize the possibility of such take.
Given the many uncertainties in predicting the quantity and types
of impacts of sound in every given situation on marine mammals, it is
common practice to estimate how many animals are likely to be present
within a particular distance of a given activity, or exposed to a
particular level of sound, based on the available science.
[[Page 43717]]
This practice potentially overestimates the numbers of marine
mammals taken for stationary activities, as it is likely that some
smaller number of individuals may accrue a number of incidences of
harassment per individual than for each incidence to accrue to a new
individual, especially if those individuals display some degree of
residency or site fidelity and the impetus to use the site (e.g.,
because of foraging opportunities) is stronger than the deterrence
presented by the harassing activity.
CALTRANS has requested authorization for the incidental taking of
small numbers of California sea lions (Zalophus californianus), Pacific
harbor seals (Phoca vitulina richardsii), harbor porpoises (Phocoena
phocoena), and gray whales (Eschrichtius robustus) incidental to
construction associated with a replacement bridge for the East Span of
the SF-OBB, in San Francisco Bay (SFB, or Bay), California.
In order to estimate the potential incidents of take that may occur
incidental to the specified activity, we must first estimate the extent
of the sound field that may be produced by the activity and then
consider in combination with information about marine mammal density or
abundance in the project area. We provided detailed information on
applicable sound thresholds for determining effects to marine mammals
as well as describing the information used in estimating the sound
fields, the available marine mammal density or abundance information,
and the method of estimating potential incidences of take, in our
Federal Register notice of proposed authorization (80 FR 23744; March
20, 2015).
Table 1 illustrated the 190 dB rms Level A harassment (injury)
threshold for underwater noise for pinniped species could be exceeded
at a distance of up to approximately 95 meters during impact pile
driving activities, and the 180 dB rms Level A harassment (injury)
threshold for cetacean species could be exceeded at a distance of up to
approximately 235 meters during impact pile driving activities.
Additionally, the 160 dB rms Level B harassment (behavioral disruption)
threshold for impulsive source underwater noise for pinniped and
cetacean species could be exceeded at a distance of up to approximately
1,000 meters during impact pile driving and the 120 dB Level B
harassment threshold could be exceeded at 2,000 meters. Note that the
actual area insonified by pile driving activities is significantly
constrained by local topography relative to the identified threshold
radii.
Marine mammal density estimates were based on marine mammal
monitoring reports and marine mammal observations made during pile
driving activities associated with the SF-OBB construction work
authorized under prior IHAs. Pacific harbor seal densities were
calculated and described in the Federal Register notice of proposed
authorization (80 FR 23744; March 20, 2015). During monitoring for the
East Span of the SF-OBB, there were 657 observations of harbor seals
made during over 210 days from 2000 to 2014. Two densities were
calculated because of the higher density of seals observed foraging
near YBI and Treasure Island. Foraging seals tended to remain in the
area for several hours while transiting seals passing under the SF-OBB
were only observed 1-2 times. Therefore, densities east of Pier E3-E8
are much lower than the density than west of Pier E3.
The area of 2,000-meter threshold for the Level B behavioral
harassment zone is 12.57 km\2\ (12,570,000 m\2\). Half of that area to
the west of Piers E3-E8 (6.29 km\2\) would have a higher density of
harbor seals which are frequently observed in the three foraging areas.
The range of seals observed within the foraging areas is 0-8 seals and
the mean is 3.6 seals per day (combined for all three areas). The other
half of the Level B harassment zone would have a lower density due to
the infrequent observations of seals moving through the area. In
addition the density of seals will vary with season therefore a density
for the spring-summer season when seals spend more time onshore as they
are pupping and molting and the fall/winter season.
This estimate of 460 harbor seal takes is above the number of seals
that have been permitted for take in previous IHAs that have been
issued related to this project. However, the estimate presented here
represents a more complete picture of the marine mammal density in the
project area and the potential for exposure to project activities.
California sea lions are based on CALTRANS observations over 15
years of monitoring on the Bay Bridge, 2000 to 2014, including baseline
monitoring in 2003 before bridge construction began. It should be noted
that monitoring was not year round and there was little monitoring
required during the period of mid-2010 to mid-2013 due to no pile
driving. During 2013 and 2014, there was a large increase in pile
driving to construct temporary falsework and for mechanical dismantling
so the current estimates of animals do include recent monitoring.
California sea lion numbers fluctuate from year to year. For example,
in 2014 no sea lions were observed in the harassment zone while in
2004, 36 sea lions were recorded near the Bay Bridge construction areas
during pile driving. The larger number of sea lions in 2004 was
probably related to a run of herring that was near the Bay Bridge and
sea lions were observed feeding on dense aggregations of herring in the
area. Therefore, an allowed take 50 sea lions is considered a
conservative estimate.
Harbor porpoises were observed near the tower of the new Bay Bridge
in 2013 and 2014. Each of those was a single animal and far out of
their normal range for the Bay. If 1 or 2 pods of porpoises were to
enter the construction area, then there might be up to 6 takes (pod
size of 2-3 porpoises). Based on this NMFS believes that an allowed
take of up to 10 harbor porpoises is conservative, but reasonable.
Gray whale take estimates were based on sighting reports collected
by the Marine Mammal Center in Sausalito (the NMFS stranding facility
for northern California). The Center collects whale sightings
information from the general public, researchers, and the U.S. Coast
Guard. For the gray whale, 5 permitted takes is likely to be a
conservative, but reasonable, estimate as they have never been observed
within any of the behavioral zones during monitoring. Additionally,
there has only been one report of a gray whale swimming under the
original East Span of the Bay Bridge a number of years ago.
Based on these results, and accounting for a certain level of
uncertainty regarding the next phase of construction, NMFS concludes
that at maximum 460 harbor seals, 50 California sea lions, 10 harbor
porpoises, and 5 gray whales could be exposed to noise levels that
could cause Level B harassment as a result of the CALTRAN' SF-OBB
construction activities. These numbers represent 1.5%, <0.01%, <0.01%
and 0.10% of the California stock harbor seal, the U.S. stock
California sea lion, the Eastern North Pacific stock gray whale, and
the San Francisco-Russian River stock harbor porpoise, respectively
(Table 2).
[[Page 43718]]
Table 2--Estimates of the Possible Maximum Numbers of Marine Mammals Taken by Level B Harassment as a Result of
the Proposed CALTRANS' SF-OBB Construction Activities
----------------------------------------------------------------------------------------------------------------
Percent
Species Stocks Level B takes population
----------------------------------------------------------------------------------------------------------------
Pinnipeds
----------------------------------------------------------------------------------------------------------------
Harbor seal................................ California......................... 460 1.5
California sea lion........................ U.S................................ 50 <0.01
----------------------------------------------------------------------------------------------------------------
Cetaceans
----------------------------------------------------------------------------------------------------------------
Gray whale................................. Eastern North Pacific.............. 5 <0.01
Harbor porpoise............................ San Francisco-Russian River........ 10 0.10
----------------------------------------------------------------------------------------------------------------
Analyses and Determinations
Negligible Impact Analysis
Negligible impact is ``an impact resulting from the specified
activity that cannot be reasonably expected to, and is not reasonably
likely to, adversely affect the species or stock through effects on
annual rates of recruitment or survival'' (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes,
alone, is not enough information on which to base an impact
determination. In addition to considering estimates of the number of
marine mammals that might be ``taken'' through behavioral harassment,
NMFS must consider other factors, such as the likely nature of any
responses (their intensity, duration, etc.), the context of any
responses (critical reproductive time or location, migration, etc.), as
well as the number and nature of estimated Level A harassment takes,
the number of estimated mortalities, effects on habitat, and the status
of the species.
To avoid repetition, the discussion of our analyses applies to all
the species listed in Table 2, given that the anticipated effects of
this pile driving project on marine mammals are expected to be
relatively similar in nature. There is no information about the size,
status, or structure of any species or stock that would lead to a
different analysis for this activity.
Pile driving, pile removal and mechanical dismantling activities
associated with the construction of a replacement bridge for the East
Span of the SF-OBB, as outlined previously, have the potential to
disturb or displace marine mammals. Specifically, the specified
activities may result in take, in the form of Level B harassment
(behavioral disturbance) only, from underwater sounds generated from
pile driving. Potential takes could occur if individuals of these
species are present in the ensonified zone when pile driving and
removal are happening.
No injury, serious injury, or mortality is anticipated given the
nature of the activity and measures designed to minimize the
possibility of injury to marine mammals. The known potential for
serious injury or mortality is minimized through the construction
method and the implementation of the planned mitigation measures. Both
vibratory hammers and impact hammers will be utilized based on local
substrate conditions. Vibratory driving will be used wherever
conditions are favorable for this technique. Vibratory driving does not
have significant potential to cause injury to marine mammals due to the
relatively low source levels produced and the lack of potentially
injurious source characteristics. Impact pile driving produces short,
sharp pulses with higher peak levels and much sharper rise time to
reach those peaks. When impact driving is necessary, required measures
(implementation of shutdown zones) significantly reduce any possibility
of injury. Given sufficient ``notice'' through use of soft start (for
impact driving), marine mammals are expected to move away from a sound
source that is annoying prior to its becoming potentially injurious.
The likelihood that marine mammal detection ability by trained
observers is high under the environmental conditions described for this
area of San Francisco Bay further enables the implementation of
shutdowns to avoid injury, serious injury, or mortality.
Effects on individuals that are taken by Level B harassment, on the
basis of reports in the literature as well as monitoring from other
similar activities, will likely be limited to reactions such as
increased swimming speeds, increased surfacing time, or decreased
foraging (if such activity were occurring) (e.g., Thorson and Reyff,
2006; HDR, 2012; Lerma, 2014). Most likely, individuals will simply
move away from the sound source and be temporarily displaced from the
areas of pile driving, although even this reaction has been observed
primarily only in association with impact pile driving. In response to
vibratory driving, pinnipeds (which may become somewhat habituated to
human activity in industrial or urban waterways) have been observed to
orient towards and sometimes move towards the sound. The pile driving
activities analyzed here are similar to, or less impactful than,
numerous construction activities conducted in other similar locations,
which have taken place with no reported injuries or mortality to marine
mammals, and no known long-term adverse consequences from behavioral
harassment. Repeated exposures of individuals to levels of sound that
may cause Level B harassment are unlikely to result in hearing
impairment or to significantly disrupt foraging behavior. Thus, even
repeated Level B harassment of some small subset of the overall stock
is unlikely to result in any significant realized decrease in fitness
for the affected individuals, and thus would not result in any adverse
impact to the stock as a whole. Level B harassment will be reduced to
the level of least practicable impact through use of mitigation
measures described herein and, if sound produced by project activities
is sufficiently disturbing, animals are likely to simply avoid the
project area while the activity is occurring.
CALTRANS' proposed activities are localized and of short duration.
The entire project area is limited to the East Span of the bridge and
its immediate surroundings. The project will require the installation
of a total of approximately 200 piles. Impact driving of pipe piles
will be limited to a maximum of 20 piles per day and proofing of the
pipe piles will not exceed a maximum of 2 piles per day--each pile
would be driven with no more than 20 blows during a one-minute
[[Page 43719]]
period. Total hammer time is scheduled to occur over 128 days between
July 15, 2015 and July 14, 2016. These localized and short-term noise
exposures may cause brief startle reactions or short-term behavioral
modification by the animals. These reactions and behavioral changes are
expected to subside quickly when the exposures cease. Moreover, the
proposed mitigation and monitoring measures are expected to reduce
potential exposures and behavioral modifications even further.
Additionally, no important feeding and/or reproductive areas for marine
mammals are known to be near the proposed action area. Therefore, the
take resulting from this CALTRANS project is not reasonably expected to
and is not reasonably likely to adversely affect the marine mammal
species or stocks through effects on annual rates of recruitment or
survival and, therefore, will have a negligible impact on the affected
species or stocks.
The project also is not expected to have significant adverse
effects on affected marine mammals' habitat, as analyzed in detail in
the ``Anticipated Effects on Marine Mammal Habitat'' section. The
project activities would not modify existing marine mammal habitat. The
activities may cause some fish to leave the area of disturbance, thus
temporarily impacting marine mammals' foraging opportunities in a
limited portion of the foraging range; but, because of the short
duration of the activities and the relatively small area of the habitat
that may be affected, the impacts to marine mammal habitat are not
expected to cause significant or long-term negative consequences.
In summary, this negligible impact analysis is founded on the
following factors: (1) The possibility of injury, serious injury, or
mortality may reasonably be considered discountable; (2) the
anticipated incidents of Level B harassment consist of, at worst,
temporary modifications in behavior with no significant adverse impacts
on habitat and; (3) the presumed efficacy of the proposed mitigation
measures in reducing the effects of the specified activity to the level
of least practicable impact. In combination, we believe that these
factors, as well as the available body of evidence from other similar
activities, demonstrate that the potential effects of the specified
activity will have only short-term effects on individuals. The
specified activity is not expected to impact rates of recruitment or
survival and will therefore not result in population-level impacts.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS finds that the total marine mammal take from
CALTRANS' construction of a replacement bridge for the East Span of the
SF-OBB will have a negligible impact on the affected marine mammal
species or stocks.
Small Numbers Analysis
Table 2 demonstrates the number of animals that could be exposed to
received noise levels that could cause Level B behavioral harassment
for the proposed work associated with the replacement bridge
construction. These numbers represent 1.5%, <0.01%, <0.01% and 0.10% of
the California stock harbor seal, the U.S. stock California sea lion,
the Eastern North Pacific stock gray whale, and the San Francisco-
Russian River stock harbor porpoise, respectively (Table 3).
The numbers of animals authorized to be taken for all species are
small relative to the relevant stocks or populations even if each
estimated taking occurred to a new individual--an extremely unlikely
scenario. For pinnipeds occurring in the vicinity of the SF-OBB
project, there will almost certainly be some overlap in individuals
present day-to-day, and these takes are likely to occur only within
some small portion of the overall regional stock, such as the number of
harbor seals that regularly use nearby haul-out rocks.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the mitigation and monitoring
measures, which are expected to reduce the number of marine mammals
potentially affected by the proposed action, NMFS finds that small
numbers of marine mammals will be taken relative to the populations of
the affected species or stocks.
Impact on Availability of Affected Species for Taking for Subsistence
Uses
There are no subsistence uses of marine mammals in the proposed
project area; and, thus, no subsistence uses impacted by this action.
Endangered Species Act (ESA)
No marine mammal species listed under the ESA are expected to be
affected by these activities. Therefore, we have determined that a
section 7 consultation under the ESA is not required.
National Environmental Policy Act (NEPA)
NMFS' prepared an Environmental Assessment (EA) for the take of
marine mammals incidental to construction of the East Span of the SF-
OBB and made a Finding of No Significant Impact (FONSI) on November 4,
2003. Due to the modification of part of the construction project and
the mitigation measures, NMFS reviewed additional information from
CALTRANS regarding empirical measurements of pile driving noises for
the smaller temporary piles without an air bubble curtain system and
the use of vibratory pile driving. NMFS prepared a Supplemental
Environmental Assessment (SEA) and analyzed the potential impacts to
marine mammals that would result from the modification of the action. A
Finding of No Significant Impact (FONSI) was signed on August 5, 2009.
A copy of the SEA and FONSI is available upon request.
Authorization
As a result of these determinations, we have issued an IHA to
CALTRANS for conducting the described activities related to the
construction of the East Span of the San Francisco-Oakland Bay Bridge,
from July 15, 2015 through July 14, 2016 provided the previously
described mitigation, monitoring, and reporting requirements are
incorporated.
Dated: July 16, 2015.
Perry Gayaldo,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2015-18021 Filed 7-22-15; 8:45 am]
BILLING CODE 3510-22-P